Neurological scans can reveal memory activity, including suppression, through the appearance of engramatic activity. (VOY: "Retrospect") After being falsely convicted of murder on Banea, in 2371, Tom Paris' punishment involved reliving the murder through the victim's eyes. This was accomplished by means of a neural implant that integrated the victim's engrams into the murdered. Because Tom was a Human, it was found that the Banean engrams that were implanted in his memory were not fully compatible with his alien neurology. As a result he lost consciousness. (VOY: "Ex Post Facto")